Conventionally, a producing method including a deposition process for producing a glass particle deposit using the OVD method, the VAD method, etc. and a transparentizing process for producing a transparent glass preform by heating this glass particle deposit is known as a glass preform producing method.
For example, Patent Document 1 discloses a precision burner, used at the time of forming a preform (glass preform), for oxidizing silicon-containing compounds not containing halides, such as octamethylcyclotetrasiloxane (OMCTS).